Measuring and Treating Brain Oxygen Levels in Open Heart Surgery

The purpose of this study is to test whether keeping the amount of oxygen delivered to the brain above a certain level during surgery and 24-hours after surgery improves recovery. Hypothesis 1: keeping the amount of oxygen delivered to the brain above a certain level during surgery and 24-hours after surgery improves cognitive and neurological outcomes after cardiac and aortic surgery. Hypothesis 2: keeping the amount of oxygen delivered to the brain above a certain level during surgery and 24-hours after surgery helps reduce major organ problems after cardiac and aortic surgery. To test our hypotheses, the investigators will conduct a randomized control trial. Patients will be randomly assigned to one of two possible study groups. In the Treatment Group, the brain oxygen level will be watched by doctors and used to guide care in the operating room and the first day in the intensive care unit after surgery. Doctors will try to keep the brain oxygen level in a normal range by adjusting your blood pressure, carbon dioxide and blood acidity levels, and blood count. In the Control Group, the doctors will not be aware of the brain oxygen level unless it falls below a level that may be dangerous. If a patient's brain oxygen falls below such a level, the doctors will adjust the blood pressure, carbon dioxide and blood acidity levels, and blood count to increase the brain oxygen level. All other procedures will be part of regular medical care and will be performed according to the standard of care.